ASKSAGE: Sage Q&A Forum - RSS feedhttps://ask.sagemath.org/questions/Q&A Forum for SageenCopyright Sage, 2010. Some rights reserved under creative commons license.Tue, 03 Mar 2015 17:25:35 +0100Is this a bug or what am I missing, simple limit computationhttps://ask.sagemath.org/question/25970/is-this-a-bug-or-what-am-i-missing-simple-limit-computation/
f=(e^(-x))/(2+ sin(x));
limit(f,x=infinity)
this yields "undefined", but the limits is clearly zero, thus I gather there's a bug or I am missing something basic . All help is appreciated. Sat, 28 Feb 2015 18:02:17 +0100https://ask.sagemath.org/question/25970/is-this-a-bug-or-what-am-i-missing-simple-limit-computation/Answer by Joe for <pre><code>f=(e^(-x))/(2+ sin(x));
limit(f,x=infinity)
</code></pre>
<p>this yields "undefined", but the limits is clearly zero, thus I gather there's a bug or I am missing something basic . All help is appreciated. </p>
https://ask.sagemath.org/question/25970/is-this-a-bug-or-what-am-i-missing-simple-limit-computation/?answer=25974#post-id-25974It certainly looks like a bug.
Limit is 0 -
WolframAlpha gives limit as 0 Sat, 28 Feb 2015 21:04:25 +0100https://ask.sagemath.org/question/25970/is-this-a-bug-or-what-am-i-missing-simple-limit-computation/?answer=25974#post-id-25974Answer by vdelecroix for <pre><code>f=(e^(-x))/(2+ sin(x));
limit(f,x=infinity)
</code></pre>
<p>this yields "undefined", but the limits is clearly zero, thus I gather there's a bug or I am missing something basic . All help is appreciated. </p>
https://ask.sagemath.org/question/25970/is-this-a-bug-or-what-am-i-missing-simple-limit-computation/?answer=25977#post-id-25977Yes it is a bug. And still present in the development version sage-6.6.beta2. I opened [ticket #17878](http://trac.sagemath.org/ticket/17878) for that. Thanks for the report! I hope it will be fixed in a next release.Sun, 01 Mar 2015 00:10:24 +0100https://ask.sagemath.org/question/25970/is-this-a-bug-or-what-am-i-missing-simple-limit-computation/?answer=25977#post-id-25977Comment by userX for <p>Yes it is a bug. And still present in the development version sage-6.6.beta2. I opened <a href="http://trac.sagemath.org/ticket/17878">ticket #17878</a> for that. Thanks for the report! I hope it will be fixed in a next release.</p>
https://ask.sagemath.org/question/25970/is-this-a-bug-or-what-am-i-missing-simple-limit-computation/?comment=26021#post-id-26021thank you kindlyTue, 03 Mar 2015 17:25:35 +0100https://ask.sagemath.org/question/25970/is-this-a-bug-or-what-am-i-missing-simple-limit-computation/?comment=26021#post-id-26021Answer by rws for <pre><code>f=(e^(-x))/(2+ sin(x));
limit(f,x=infinity)
</code></pre>
<p>this yields "undefined", but the limits is clearly zero, thus I gather there's a bug or I am missing something basic . All help is appreciated. </p>
https://ask.sagemath.org/question/25970/is-this-a-bug-or-what-am-i-missing-simple-limit-computation/?answer=25992#post-id-25992If Maxima is unsatisfactory, try SymPy:
sage: f = exp(-x) / (2 + sin(x))
sage: import sympy
sage: sympy.limit(f,x,oo)
0
Sun, 01 Mar 2015 08:20:18 +0100https://ask.sagemath.org/question/25970/is-this-a-bug-or-what-am-i-missing-simple-limit-computation/?answer=25992#post-id-25992Comment by userX for <p>If Maxima is unsatisfactory, try SymPy: </p>
<pre><code>sage: f = exp(-x) / (2 + sin(x))
sage: import sympy
sage: sympy.limit(f,x,oo)
0
</code></pre>
https://ask.sagemath.org/question/25970/is-this-a-bug-or-what-am-i-missing-simple-limit-computation/?comment=26020#post-id-26020thank you, appreciate the sympy tipTue, 03 Mar 2015 17:25:27 +0100https://ask.sagemath.org/question/25970/is-this-a-bug-or-what-am-i-missing-simple-limit-computation/?comment=26020#post-id-26020